'Enough is enough', US tells UN on N Korea

North Korean leader Kim Jong-un meets scientists and technicians in the field of researches into nuclear weapons in this photo released by North Korea’s Korean Central News Agency in Pyongyang last year. Photo: Reuters

Nikki Haley, the US ambassador to the United Nations, yesterday told an emergency meeting of the Security Council that "enough is enough", adding that while America does not want war, "our country's patience is not unlimited".

Nikki Haley, the US ambassador to the United Nations, yesterday told an emergency meeting of the Security Council that "enough is enough", adding that while America does not want war, "our country's patience is not unlimited".

Military leaders in South Korea claim to have seen indications that the North is preparing an attack and believe it has successfully miniaturised a nuclear weapon to fit onto an intercontinental ballistic missile.

Sunday's nuclear test by North Korea had an estimated strength of 50 kilotons - three times bigger than the US device that destroyed Hiroshima in 1945 - Seoul defence ministry officials told a parliamentary briefing yesterday, as they agreed "it is time to strengthen" a military response.

The South responded to the nuclear test, which the North claimed was of a hydrogen bomb, with live-fire drills off its eastern coast yesterday that were meant to simulate an attack on the North's main test site.

North Korea responded that its enemies are "hell-bent on escalating confrontation", as it launched a scathing attack on the "warmongers" in Seoul.

The UN Security Council is holding its second emergency meeting about North Korea in a week in New York to discuss responses to the test. Last August, it imposed sanctions targeting North Korean exports.

United Nations US ambassador Nikki Haley speaks with her Chinese counterpart before the Security Council meeting. Photo: Getty Images

China has warned North Korea against proceeding with plans to launch another ballistic missile, saying it should not worsen tensions, but said Donald Trump's trade threat was "unacceptable".

America has warned that any threat to itself or its allies would be met with a "massive military response", but British Foreign Secretary Boris Johnson cautioned against a military strike.

Ms Haley urged the UN Security Council to impose the "strongest possible measures" against North Korea.

"Only the strongest sanctions will enable us to resolve this problem through diplomacy," she said.

"When a rogue regime has a nuclear weapon and an ICBM pointed at you, you do not take steps to lower your guard.

"No one would do that. We certainly won't."

The United States, Britain, France, Japan and South Korea requested the urgent meeting after North Korea detonated what it described as a hydrogen bomb designed for a long-range missile.

Ms Haley declared that the "time for half measures is over", suggesting the council must significantly ratchet up the pressure with biting sanctions to be decided in a new resolution.

The US ambassador did not spell out what measures Washington would support, but diplomats have indicated that an oil embargo would have a crippling effect on the North Korean economy.

Japan, France and Britain called for the swift adoption of a new sanctions resolution, but the call was expected to face opposition from Russia and China which maintain that sanctions alone will not resolve the crisis.

Japan has urged the UN Security Council to agree on a plan to draft a new sanctions resolution to punish North Korea after its sixth nuclear test.

The Brics group of five major emerging economies on Monday denounced North Korea's latest nuclear test at a summit in China that seeks to enlarge the organisation's presence on the world stage.

The nations - Brazil, Russia, India, China and South Africa - agreed in a joint declaration to strengthen cooperation against a range of organisations it described as terrorist, including some based in Pakistan.

In the 43-page declaration, Chinese President Xi Jinping, Indian Prime Minister Narendra Modi, Russian President Vladimir Putin, Brazilian President Michel Temer and South African President Jacob Zuma said they would work together to improve global economic governance to foster "a more just and equitable international order".

They also strongly condemned North Korea's sixth - and most powerful - nuclear test that took place Sunday and has overshadowed the two-day Brics summit in the southeastern Chinese city of Xiamen that China is using as a showcase for its growing international status.

Meanwhile, neutral Switzerland said it was prepared to act as mediator to help resolve the North Korea crisis, including by hosting ministerial talks, Swiss President Doris Leuthard said.

She said Swiss troops were deployed on the demarcation zone between South Korea and North Korea and the country had a long history of neutral diplomacy. But China and the United States had to take their share of responsibility, she added.

"We are ready to offer our role... as a mediator," Ms Leuthard told a news conference. "It is really time now to sit down at a table. Big powers have a responsibility."